1. Field of the invention
This invention relates to a data slicer for converting detection signals into digital signals in a data transmission system.
2. Related art
A data slicer organized as shown in FIG. 1 has been well known in the art. That is, in a synchronization data transmission system, the detection signal is applied through a first low-pass filter 511 to a voltage comparator 512, and the output of the first low-pass filter 511 is applied to a second low-pass filter 513. In the second low-pass filter 513, a reference voltage is formed, and applied to the voltage comparator 512. In the comparator 512, the detection signal received through the first low-pass filter 511 is compared with the reference voltage, to form a digital signal.
In the above-described conventional data slicer, the second low-pass filter 513 detects the maximum voltage value and the minimum voltage value of the detection signal, obtains the average value of those voltage values thus detected, and outputs it as the reference voltage. Hence, the conventional data slicer suffers from a difficulty that the reference value is changed with the variation in frequency of the detection signal.